14/08/2018

Just like horses, dogs and cats, exotic animals have a range of microorganisms that live with and on them. Some of these microorganisms are normal, whilst others are dangerous parasites that can cause serious disease. In between these two extremes are the opportunistic microorganisms that only cause disease when their host (the exotic animal) is unwell.

Below we have included a discussion on some of the more frequently encountered parasites, and how you can recognize the signs of infection in your exotic pets.

Rabbits

Important tip #1: Frontline (fipronil) is toxic to rabbits.

Mites
The two most common forms of mites in rabbits are the ear mite Psoroptes cuniculi and the fur mite Cheyletiella parasitovax. The ear mite can cause severe damage to the external ear and affected rabbits have crusting of their ears, are very itchy and will frequently shake their head. Infections of the fur mite Cheyletiella tend to be less severe and cause a characteristic ‘walking dandruff’ appearance to the skin. Affected rabbits will often lose patches of their coat.
The fur mite can be transmitted to people in severe infestations and may also be passed to cats and dogs. Fortunately, there are several effective treatments for mites in rabbits including Revolution and ivermectin. However, care must be taken with the dosing of these medications, as they are often packaged for cat and dog sizes.

Fleas
There are three main fleas that can affect rabbits; the cat flea, the dog flea and the rabbit flea. The rabbit flea is rare in pet rabbits. In contrast, both cat and dog fleas can readily affect rabbits when they are housed with infested cats or dogs.
All these fleas cause similar signs in affected rabbits. These rabbits have dull coats, are itchy and lose their hair in patches. Fortunately, there are effective flea treatments for rabbits that we can help you with if needed. Any in-contact animals should also be treated and for breeding rabbits, excellent hygiene and environmental decontamination is vital.

Coccidiosis
The term coccidiosis refers to the disease caused by several species of protozoa (single celled microorganisms) in the subclass Coccidia. These parasites cause two forms of disease depending on where they live in the body; the intestines or the liver. The liver form is most commonly subclinical, meaning rabbits with good immune systems or those exposed to small doses do not show any disease. The condition become more severe where hygiene is poor, particularly in overcrowded populations. In these situations, the liver form of coccidia can be fatal.
The intestinal forms are more familiar and typically cause disease in young rabbits. Those agreed between 1-4 months old are most vulnerable, and the symptoms can include weight lost, lack of weight gain despite a good appetite, diarrhea and even death.
If caught early, both the liver and intestinal forms can be treated effectively with drugs such as sulfonamides and toltrazuril, as well as good hygiene practices.

Encephalitazoon Cuniculi
This is a parasite that is found in approximately 35-60% of the rabbit population, depending on the country and area. It is a fungal-like parasite that can live in the brain, kidneys or eye of rabbits and often causes little to no disease. However, in rabbits with a poor or suppressed immune system, this parasite can spread and cause damage to local tissues. This means affected rabbits can develop ocular (eye), neurological (brain) or kidney disease, or a combination of these, depending on the severity of the disease.
Clinical signs of the neurological form include head tilts, paralysis of two or more limbs, seizure-like activity and rolling. The kidney form causes rabbits to urinate and drink more and can progress to kidney failure. The ocular form causes cataracts or white plaques in the eye.
There is no cure for E. cuniculi, but there are medications such as fenbendazole that can be used to manage the parasite. Good hygiene and prevention plans can also reduce the chance of in-contact rabbits being affected, as the parasite spreads in the urine and from the mother to her kits during or before birth.

Guinea Pigs

Important tip #2: Parasites are often secondary to other disease.

Mites
The most common mite causing disease in guinea pigs is Trixacarus caviae. This parasite can be passed between guinea pigs in direct contact with each other or guinea pigs may carry the mite in small numbers, and not show any signs of disease.
Trixacarus causes severe skin disease in affected guinea pigs. Symptoms range from intense itchiness and fur loss, to self-trauma and seizures. In the early stages of infection, the mites can be readily treated with ivermectin or in some cases, selamectin (Revolution). In severe cases, guinea pigs are often underweight, require supportive antibiotic, pain relief and sedation if active seizures are present.
Mites are rare in healthy guinea pigs, and most have underlying causes of immunosuppression, such as vitamin C deficiency, poor hygiene or fighting between other guinea pigs.

Ringworm
Ringworm is the term used to describe a fungal infection, which is most commonly due to Trichophyton species in guinea pigs. Many guinea pigs will carry these fungi normally without any concerns. However, in immunosuppressed guinea pigs (particularly the juveniles), ringworm can overgrow and cause hair loss. The main issue in these cases is finding the underlying cause of the poor immune system, which are very similar to the causes that lead to mite infection.

Ferrets

Important tip #3: Prevention is easier than cure.

Heartworm
Just like in dogs and cats, ferrets can also acquire heartworm. Heartworm is caused by Dirofilaria imminitis, which is a worm that is transmitted by affected mosquitoes. Whilst the disease is rare in ferrets, the condition is very severe and once clinical signs are observed the disease is usually in its end stages. Symptoms of heart worm include difficulty breathing, exercise intolerance and being pale. The worm is also difficult to diagnose and requires x-rays and often ultrasound of the heart to confirm.
Treatment is possible, but prevention is much safer and more effective. Ferrets can be given moxidectin, selamectin or ivermectin regularly to prevent being affected by this condition.

Fleas
The most common fleas affecting ferrets are those also found on dogs and cats. They are transmitted by direct contact from an affected animal and can usually be identified by the characteristic ‘flea dirt’ that the adult fleas produce.
Symptoms include itching or in some cases, a hypersensitivity reaction where a single bite can cause severe itching. In most ferrets the condition is readily managed with topical moxidectin or imidacloprid, and environmental decontamination.

Rats & Mice

Important tip #4: Not all skin diseases are due to infections.

Mites
There are many species of mites that affect rats and mice, and they all vary in their severity. Rat fur mite (Radfordia spp) is common but only heavy infestations cause disease. The ear mite (Notoedres spp) can cause dermatitis of the ears in mice and rats but is less common.
The main concern with mites in rodents is the intense itchiness they can cause. Affected rats and mice often self-traumatize their skin, leading to bacterial infections and hair loss. These individuals are often painful and require a variety of antibiotics, pain relief and mite treatment, and many get recurrent infections.
The main goal of treatment is to address the cause of the immunosuppression that allows the mites to overgrow, before secondary infections occur. These causes can include overcrowding, poor nutrition or changes in their environment.

Ringtail
This condition causes characteristic circular constrictions of the tail in both rats and mice. It most commonly occurs in very young rodents where low humidity in their environment causes their skin to dry and constrict or even amputation parts of their tail. Humidity levels below 40% appear to be the main cause of this condition.
Treatment includes pain relief and increasing the humidity in their environment.